/Engine/Source/Runtime/Engine/Classes/Engine/LocalPlayer.h
Retrieves this player's name/tag from the online subsystem if this function returns a non-empty string, the returned name will replace the "Name" URL parameter passed around in the level loading and connection code, which normally comes from DefaultEngine.ini
Name of player if specified (by onlinesubsystem or otherwise), Empty string otherwise
virtual [FString](API\Runtime\Core\Containers\FString) GetNickname() const